support scala 2.13 and scala 3 build for codegen lib (#181)

* support scala 2.13 and scala 3 build for codegen lib

* Update build.sbt

* rework build

.github/workflows/build-test.yml

@@ -65,7 +65,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        SCALA_VERSION: [2.12, 2.13, 3.3]
+        SCALA_VERSION: [2.12.18, 2.13.11, 3.3.1]
         JAVA_VERSION: [8, 11]
     steps:
       - name: Checkout
@@ -83,8 +83,9 @@ jobs:
         uses: coursier/cache-action@v6
 
       - name: Compile and test for JDK ${{ matrix.JAVA_VERSION }}, Scala ${{ matrix.SCALA_VERSION }}
-        run: sbt ++${{ matrix.SCALA_VERSION }}.* test
-
+        run: |-
+          sbt ++${{ matrix.SCALA_VERSION }} test
+          sbt ++${{ matrix.SCALA_VERSION }}! codegen/test
 
   test-sbt:
     name: sbt scripted tests

.github/workflows/publish-nightly.yml

@@ -27,6 +27,8 @@ jobs:
         run: |-
           cp .jvmopts-ci .jvmopts
           sbt +publish
+          sbt ++2.13.11! codegen/publish
+          sbt ++3.3.1! codegen/publish
         env:
           NEXUS_USER: ${{ secrets.NEXUS_USER }}
           NEXUS_PW: ${{ secrets.NEXUS_PW }}

build.sbt

@@ -66,7 +66,15 @@ lazy val codegen = Project(id = "codegen", base = file("codegen"))
     (assembly / assemblyOption) := (assembly / assemblyOption).value.withPrependShellScript(
       Some(sbtassembly.AssemblyPlugin.defaultUniversalScript(shebang = true))),
     crossScalaVersions := Dependencies.Versions.CrossScalaForPlugin,
-    scalaVersion := scala212)
+    scalaVersion := scala212,
+    Compile / unmanagedSourceDirectories ++= {
+      if (scalaBinaryVersion.value == "2.12") {
+        Seq.empty
+      } else {
+        Seq(
+          project.base / "src" / "main" / "scala-2.13+")
+      }
+    })
   .settings(addArtifact(Compile / assembly / artifact, assembly))
   .settings(addArtifact(Artifact(pekkoGrpcCodegenId, "bat", "bat", "bat"), mkBatAssemblyTask))
 

codegen/src/main/scala-2.13+/org/apache/pekko/grpc/gen/CodeGenerator.scala

@@ -0,0 +1,48 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * license agreements; and to You under the Apache License, version 2.0:
+ *
+ *   https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * This file is part of the Apache Pekko project, which was derived from Akka.
+ */
+
+/*
+ * Copyright (C) 2018-2021 Lightbend Inc. <https://www.lightbend.com>
+ */
+
+package org.apache.pekko.grpc.gen
+
+import com.google.protobuf.ExtensionRegistry
+import com.google.protobuf.compiler.PluginProtos.CodeGeneratorRequest
+import com.google.protobuf.compiler.PluginProtos.CodeGeneratorResponse
+import protocbridge.Artifact
+
+/**
+ * Code generator trait that is not directly bound to scala-pb or protoc (other than the types).
+ */
+trait CodeGenerator {
+  import CodeGenerator._
+
+  /** Generator name; example: `pekko-grpc-scala` */
+  def name: String
+
+  def run(request: CodeGeneratorRequest, logger: Logger): CodeGeneratorResponse
+
+  /** Takes Scala binary version and returns suggested dependency Seq */
+  def suggestedDependencies: ScalaBinaryVersion => Seq[Artifact]
+
+  def registerExtensions(registry: ExtensionRegistry): Unit = {}
+
+  final def run(request: Array[Byte], logger: Logger): Array[Byte] = {
+    val registry = ExtensionRegistry.newInstance
+    registerExtensions(registry)
+    run(CodeGeneratorRequest.parseFrom(request, registry), logger: Logger).toByteArray
+  }
+}
+
+object CodeGenerator {
+
+  /** Holds the prefix of a given Scala binary version */
+  case class ScalaBinaryVersion(prefix: String)
+}

codegen/src/main/twirl/templates/ScalaClient/Client.scala.txt

@@ -34,7 +34,7 @@ import pekko.grpc.PekkoGrpcGenerated
 @{
   def withSingleResponse(stmt: String) = Set("import pekko.grpc.scaladsl.SingleResponseRequestBuilder", stmt)
   def withStreamResponse(stmt: String) = Set("import pekko.grpc.scaladsl.StreamResponseRequestBuilder", stmt)
-  service.methods.flatMap { method: org.apache.pekko.grpc.gen.scaladsl.Method =>
+  service.methods.flatMap { (method: org.apache.pekko.grpc.gen.scaladsl.Method) =>
 
     val statements = method.methodType match {
       case org.apache.pekko.grpc.gen.Unary => withSingleResponse("import pekko.grpc.internal.ScalaUnaryRequestBuilder")

project/Dependencies.scala

@@ -15,6 +15,7 @@ import buildinfo.BuildInfo
 
 object Dependencies {
   object Versions {
+    // Update the .github workflows when these scala versions change
     val scala212 = "2.12.18"
     val scala213 = "2.13.11"
     val scala3 = "3.3.1"

project/plugins.sbt

@@ -17,7 +17,7 @@ addSbtPlugin("lt.dvim.authors" % "sbt-authors" % "1.3")
 addSbtPlugin("org.scalameta" % "sbt-scalafmt" % "2.4.6")
 addSbtPlugin("de.heikoseeberger" % "sbt-header" % "5.9.0")
 addSbtPlugin("com.thesamet" % "sbt-protoc" % sbtProtocV)
-addSbtPlugin("com.typesafe.sbt" % "sbt-twirl" % "1.5.1")
+addSbtPlugin("com.typesafe.play" % "sbt-twirl" % "1.6.1")
 addSbtPlugin("com.eed3si9n" % "sbt-assembly" % "2.1.1")
 addSbtPlugin("com.eed3si9n" % "sbt-buildinfo" % "0.11.0")
 addSbtPlugin("io.spray" % "sbt-revolver" % "0.9.1")